MDF splitting

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by Walt posted 08-18-2010 04:52 PM 1750 views 1 time favorited 8 replies Add to Favorites Watch
View Walt's profile


211 posts in 2260 days

08-18-2010 04:52 PM

I have been building a shop table project that has MDF as a frame. The plans called for butt joint, screwed and glued but even though I predrilled and used wax on the screws I still had some splitting of the end of the MDF piece. Is there a good way to prevent this

-- Walt Wilmington Delaware,

8 replies so far

View Bill White's profile

Bill White

4408 posts in 3382 days

#1 posted 08-18-2010 04:55 PM

The short answer is NO. It is just the nature of the beast.


View wseand's profile


2754 posts in 2463 days

#2 posted 08-18-2010 05:02 PM

Walt like Bill said it is what it is. Can you do a Dado on this project and Glue and nail it. Either that or some sort of cleat.

-- Bill - "Freedom flies in your heart like an Eagle" Audie Murphy

View Keith Fenton's profile

Keith Fenton

325 posts in 2341 days

#3 posted 08-18-2010 05:04 PM

Like Bill said, it will happen. To minimize splitting I predrill with a big enough bit (slightly bigger than normal), keep screws more than 3” away from the end of the sheet, keep the screws over 6” apart and don’t screw them in overly tight. IMO screws don’t accomplish all that much in MDF and I basically only use a minimal amount of screws to help with assembly and gluing.

-- Scroll saw patterns @

View jimp's profile


208 posts in 3182 days

#4 posted 08-18-2010 05:38 PM

When screwing into the end of MDF, use confirmat screws. They are designed for MDF. Here is some information on confirmat screws from Mcfeely's.

I also agree with SCROLL3R about staying away from the end of the sheet. The confirmat screws will help a lot.

-- - Jim, Carroll, OH

View Walt's profile


211 posts in 2260 days

#5 posted 08-18-2010 06:11 PM

Boy am I suprised to get answers this quick. Thanks. The way I handled these cracks was to fill them with epoxy and clamp them tight. The next day every thing was tight and square. The repair is very noticable but I will be covering it with plywood for a shelf so no one will know :)

-- Walt Wilmington Delaware,

View Ger21's profile


1047 posts in 2552 days

#6 posted 08-19-2010 04:05 AM

If it splits, your predrilled hole is too small. However, a better method is to use a shallow dado, maybe 1/8” or even slightly less. This will keep the board from splitting.

-- Gerry,

View jusfine's profile


2405 posts in 2347 days

#7 posted 08-19-2010 04:45 AM

I have drilled holes in the edge of the MDF (where I had to fasten close to an end or edge) with a 3/8 brad point bit, glued and inserted a 3/8 dowel, marked the location, then predrill and place your screws into the dowel, and it will hold and not split…

-- Randy "You are judged as much by the questions you ask as the answers you give..."

View Walt's profile


211 posts in 2260 days

#8 posted 08-19-2010 02:00 PM

Thanks for all the good information. The project I am working on calls for a rail to hang a bench slave system using dowels to hold material against the from of the table. The plans call for MDF for this rail system but I am switchiing it to 3/4 inch oak since it will be under some stress.

-- Walt Wilmington Delaware,

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics